MATH 225N WEEK 8 FINAL EXAM STATISTICS
CERTIFICATION EVALUATION EXAMS 2026
COMPLETE QUESTIONS AND ANSWERS
GUARANTEED TO PASS
◉ ensures a normally shaped sampling distribution of sample
means. Answer: minimum sample size of about 30, is needed.
However, we do not need this large of a sample if the original
population (i.e. the parent population) is approximately normally
distributed
◉ mean = 518 (Mean of population approximates sample mean)
17.16 (σS/SD of these sample means =σ/√η=94/√30=17.16)
Normal (sampling size is over 30). Answer: ,
population mean 518
population standard deviation 94
number sampled 30
What the mean of the samples means?
What is the SD of these samples?
What shape will this sampling distribution have?
, ◉ A) 518, 17.16, bell B). Answer: The population mean SAT Math
score for 2006 was 518 with a standard deviation of 94. Several
random
samples of thirty students who took the SAT were selected and the
average SAT Math scores were determined.
A) What should the mean of these sample means be? What should
the standard deviation of these
sample means be? What shape will this sampling distribution have?
B) One sample of 30 students who took the SAT will be randomly
selected and the mean SAT Math score
determined. What is the probability the sample mean SAT Math
score is higher than 530?
◉ point estimate. Answer: In simple terms, any statistic can be a . A
statistic is an estimator of some parameter in a population. For
example: The sample standard deviation (s) is a point estimate of
the population standard deviation (σ). The sample mean (̄x) is a
point estimate of the population mean, μ
◉ (t-Interval option)
135.4
116.0, 154.8
19.4 (154.8 - 135.4). Answer: The following 10 values were obtained
by checking the LDL cholesterol levels of adult males. Assume these
values are from an approximately normal distribution.
CERTIFICATION EVALUATION EXAMS 2026
COMPLETE QUESTIONS AND ANSWERS
GUARANTEED TO PASS
◉ ensures a normally shaped sampling distribution of sample
means. Answer: minimum sample size of about 30, is needed.
However, we do not need this large of a sample if the original
population (i.e. the parent population) is approximately normally
distributed
◉ mean = 518 (Mean of population approximates sample mean)
17.16 (σS/SD of these sample means =σ/√η=94/√30=17.16)
Normal (sampling size is over 30). Answer: ,
population mean 518
population standard deviation 94
number sampled 30
What the mean of the samples means?
What is the SD of these samples?
What shape will this sampling distribution have?
, ◉ A) 518, 17.16, bell B). Answer: The population mean SAT Math
score for 2006 was 518 with a standard deviation of 94. Several
random
samples of thirty students who took the SAT were selected and the
average SAT Math scores were determined.
A) What should the mean of these sample means be? What should
the standard deviation of these
sample means be? What shape will this sampling distribution have?
B) One sample of 30 students who took the SAT will be randomly
selected and the mean SAT Math score
determined. What is the probability the sample mean SAT Math
score is higher than 530?
◉ point estimate. Answer: In simple terms, any statistic can be a . A
statistic is an estimator of some parameter in a population. For
example: The sample standard deviation (s) is a point estimate of
the population standard deviation (σ). The sample mean (̄x) is a
point estimate of the population mean, μ
◉ (t-Interval option)
135.4
116.0, 154.8
19.4 (154.8 - 135.4). Answer: The following 10 values were obtained
by checking the LDL cholesterol levels of adult males. Assume these
values are from an approximately normal distribution.
